aitearn



UNITED STATES PATENT OFFICE.

THOMAS AHEARN, OF OTTAIVA, CANADA.

LCTRIC WATER-H EATER.

SPECIFICATION forming part of Letters Patent No. 481,291, dated August23, 1892.

Application filed April 9, 1892. Serial No. 428,425. (No model.)

To all whom it may concern:

Be it known that I, THOMAS AHEARN, of the city of Ottawa, in theProvince of Ontario, and in the Dominion of Canada, have inventedcertain new and usefullrnprovements in Electric Tater-Heaters; and I dohereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawings, forming a part hereof.

My invention, which will be hereinafter fully set forth and claimed,relates to devices for heating water by means of an electric current.

Figure l is an elevation of my improved water-heater. Fig. 2 is avertical section of the same on line no, Fig. l. Fig. 3 is a horizontalsection on line y y, Figs. l and 2.

A is an open vessel, preferably metallic and a good conductor ofheat-such as copper, tin, or thin cast-iron-adapted to hold water. Uponthis are placed strips of insulating ma terial B, such as asbestus. Uponthis insulation is wound a coil of wire or strip C of refractorymaterial having a high electric resistance-such as German silver-and theterminals connected with leads c c of an electric circuit. The vesselthus insulated, coiled, and connected is placed in a larger vessel orcontainer D, large enough to leave an annular space all round the innervessel A and also a space between the two bottoms. The latter space ispacked with a good non-conductor of heat and electricity E-such asasbestus-an d the annular space is iilled with powdered Whiting,fire-clay, or other refractory material F, which is also a non-conductorof electricity. The interior of the vessel D is also lined with asbestusor other non-conductor of heat E. The top of the annular space is madeup with a ring cover G, provided with insulators g g, through which theleads c c are passed. The inner vessel Ais provided with a removablehollow cover II, the interior of which is packed with a goodnonconductor of heat, such as asbestus h. An opening 7i is provided insaid cover convenient for filling the vessel.

To the interior of the cover II may be attached a closed water-tightvessel H of such a size as to reduce the water-space in the vessel A andform an annular space around said vessel Il and a space between itsbottom and that of the vessel A.

I is the draw-off pipe, preferably secured in the bottom of the vessel Aand passing through the bottom of the container D and provided with asuitable faucet t'. To said pipe I may be attached a branch I, providedwith an elbow i', in which a gage-glass I is secured. The outer vesselor container D may be further packed externally with a nonconductor ofheat and suitably lagged with wood or other material, if desired. Thevessel A is filled with water, the level of which may be readilyobserved in the gage-glass I. A switch being provided in the leads c cat a suitable point, the current may be turned on or off when desired.The coil C is of such a sectional area that it is heated by the passageof a current without being fused. The heat thus created in the coil isconducted by the filling F to the vessel A and by it communicated to thewater in said vessel. The water-level in the vessel A may be maintaineduniformlyby any well-known automatic regulating device suitablyconnected with said vessel.

I claim as my inventionl. In an electric water-heater, the combinationof an insulated open water-tight vessel A, a coil of refractory wire orstrip O, of low electric conductivity, having its terminals connected byleads passing through insulators, a containing-vessel D, linedinternally with a layer of non-heat-conducting material and large enoughto form an annular space around said inner vessel and affording spacefor a thick layer of non-conducting material at the bottom, a covering Gon the annular space containing insulators to pass the leads of thecircuit, a removable hollow cover II, a draw-off pipe I, with faucet,and a iilling of powdered Whiting, lire-clay, or other refractorymaterial in the space between the inner and outer vessel and in thecover, substantially as set forth.

2. In an electric water-heater, the combination of an open water-tightvessel A, insulating-strips B, laid upon the exterior of said IOC)Vessel, a coil C, Wound upon said insulating- I on said pipe, and agage-glass I secured Strips and connected with a circuit, a hollow tosaid branch, substantially as Set forth. 1 o Cover H, lled Withnon-conductors of heat and provided With an opening h', a Watertightvessel II', connected to the bottom of said cover and smaller than thevessel A, a draw-off pipe I, secured in the bottom of the vessel A andprovided with faucet, L branch In testimony whereof I have signed in thepresence of the undersigned witnesses.

T. AI'IEARN. Witnesses:

A. HARVEY, A. TRoWsE.

